Damast Shari, Tien Christopher J, Young Melissa, Altwerger Gary, Ratner Elena
Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT, USA.
Department of Obstetrics and Gynecology, Yale University School of Medicine, New Haven, CT, USA.
J Contemp Brachytherapy. 2022 Feb;14(1):66-71. doi: 10.5114/jcb.2022.113058. Epub 2022 Jan 28.
To ease anesthesia and inpatient strain during the COVID-19 pandemic, our institution's policy for hybrid intracavitary-interstitial brachytherapy (IC/ISBT) for cervical cancer (CC) was modified from multiple applications (MA) treated over 2 separate weeks (7 Gy × 4) to a single-application (SA), treated within 1 week (8 Gy × 3). Here, we assessed dosimetric quality of the SA hybrid IC/ISBT approach and report our early outcomes.
This was an IRB-approved retrospective review of CC patients treated with magnetic resonance imaging (MRI)-guided hybrid IC/ISBT between April 1, 2020 and December 31, 2020 (COVID cohort). Treatment parameters and quality indicators were compared to hybrid IC/ISBT cases treated in 2 years prior (pre-COVID cohort). Differences between cohorts were evaluated with the Mann-Whitney -test.
In the COVID compared to pre-COVID cohort, median high-risk clinical target volume (HR-CTV) was similar: 33.3 vs. 33.9 cc, as was cumulative HR-CTV D: 81.2 vs. 80.9 Gy. Organ-at-risk D values and recto-vaginal point doses were similar. Median number of channels loaded was increased to 6 vs. 4 ( = 0.002), but percentage of total dwell time allocated to needles remained similar: 13% vs. 15%. Median implant HR-CTV D was higher: 107.8% vs. 98.4% ( = 0.001), and there was a trend toward reduced overall treatment time (OTT): 44 days vs. 53 days ( = 0.1). Local control was achieved in all patients, but mucosal toxicity was higher in the COVID group, with grade 2 or higher vaginal, genitourinary, or gastrointestinal events recorded in 56% of the patients.
The SA hybrid IC/ISBT approach utilized during the COVID-19 pandemic maintained similar plan characteristics as pre-pandemic MA hybrid cases, while simultaneously reducing anesthesia, inpatient resources, and OTT. Local control outcomes demonstrate the regimen was effective; however, given the increased risk of mucosal toxicity, we conclude that the SA regimen should be considered only when a MA schedule is not feasible.
为缓解新型冠状病毒肺炎（COVID-19）大流行期间的麻醉和住院压力，我们机构将宫颈癌（CC）的混合腔内-组织间近距离放射治疗（IC/ISBT）策略从分2周进行多次照射（MA，7 Gy×4）改为1周内单次照射（SA，8 Gy×3）。在此，我们评估了SA混合IC/ISBT方法的剂量学质量并报告了我们的早期结果。
这是一项经机构审查委员会（IRB）批准的对2020年4月1日至2020年12月31日期间接受磁共振成像（MRI）引导的混合IC/ISBT治疗的CC患者的回顾性研究（COVID队列）。将治疗参数和质量指标与前2年接受混合IC/ISBT治疗的病例（COVID前队列）进行比较。采用Mann-Whitney检验评估队列之间的差异。
与COVID前队列相比，COVID队列中高危临床靶区体积（HR-CTV）中位数相似：分别为33.3与33.9 cc，累积HR-CTV D也相似：分别为81.2与80.9 Gy。危及器官的D值和直肠阴道点剂量相似。中位加载通道数增加至6个与4个（P = 0.002），但分配给针的总驻留时间百分比保持相似：分别为13%与15%。中位植入HR-CTV D更高：分别为107.8%与98.4%（P = 0.001），并且总体治疗时间（OTT）有缩短趋势：分别为44天与53天（P = 0.1）。所有患者均实现了局部控制，但COVID组的黏膜毒性更高，56%的患者记录有2级或更高等级的阴道、泌尿生殖系统或胃肠道事件。
COVID-19大流行期间采用的SA混合IC/ISBT方法与大流行前的MA混合病例保持相似的计划特征，同时减少了麻醉、住院资源和OTT。局部控制结果表明该方案是有效的；然而，鉴于黏膜毒性风险增加，我们得出结论，仅当MA方案不可行时才应考虑SA方案。
